The clinical application of lasers in ophthalmology is schematized, showing for each anatomic eye structure, pathologies that may be treated through this procedure. In the cornea, the unusual laser practice for suture removals and the promising possibility of the excimer laser in refractive surgery are discussed. In the iris, the camerular angle, and the ciliary body, the laser application is essentially used to treat the glaucoma and other situations that are not so frequent. The capsulotomy with YAG LASER is used in the treatment of structures related with crystalline and, at least, the treatment of the retina and choroid pathology is expanded. A. A. explained the primordial interest and important of laser in the diabetic retinopathy treatment and some results in patients with more than 5 years of evolution are: 55 of the patients with proliferative diabetic retinopathy (RDP) treated for more than 5 years noticed their vision improved or stabilized; 5 years after treating patients with PDR, 49.3 had their vision stabilized or even improved, provided the diabetics had declared itself more than 20 years ago, versus 61.7 provided the diabetics had declared itself less than 20 years before; finally, 53.8 of the patients under 40-years-old when the diabetics was diagnosed, had their vision improved or at least stabilized 5 years after the beginning of the treatment. On the other side, when patients were over 40 years old when the diabetics was diagnosed percentage increased to 55.9. This study was established in the follow-up of 149 cases over 10 years.